This invention relates, in general, to optical signal processing, and more particularly, to a device for optical signal frequency conversion and mixing.
Optical signal processing systems utilize modulated light signals to transmit information. Light may be modulated by applying a signal to a laser bias. This method is limited in application because laser dynamics limit how fast the laser can be modulated before problems of destructive resonance arise. Typically, a laser can be modulated up to frequencies of 4 GHz, however, higher frequencies may be obtained in special cases. Thus, applying a signal above approximately 4 GHz to a laser bias results in a noisy and unstable bias. It is desirable to modulate light at higher frequencies because more information may be transmitted at higher frequencies.
An alternative way of modulating light is by shining light on bulk materials. This method is also unacceptable because there is a significant loss of light when the material is modulated. These optical systems, typically comprise large optical systems comprising Bragg cells. Thus, it would be desirable to reduce the size, weight, and power of these optical systems. In addition, the bulk materials are incompatible with semiconductor materials and thus can not be integrated into a monolithic device.
A third way of modulating light is by transferring the optical signal to an electrical signal, then processing that electrical signal and converting it back to an optical signal. This process is very inefficient by nature due to energy lost in converting from an optical signal to an electrical signal.
By now, it should be appreciated that it would be advantageous to provide an improved system for optical signal processing.
Accordingly, it is an object of the present invention to provide an improved device for optical signal processing.
Another object of the present invention is to provide an improved device which accomplishes optical signal frequency conversion.
A further object of the present invention is to provide an optical signal processing system that can be utilized at much higher frequencies.
An additional object of the present invention is to provide a device which provides for optical signal mixing and frequency selection.
A further object of the present invention is to provide an optical processing system that is smaller than prior art optical systems.